An antenna positioning system is generally used in a wireless communication system where a particular antenna orientation is required to establish and maintain a communication link with a target device. Target devices can include satellites, planes, ground-based vehicles, stationary ground-based targets and the like.
A positioning system for communication with these target devices may have particular performance requirements. For instance, the positioning system may be required to provide a relatively large angular range. In addition, the wireless communication system may require relatively high positioning accuracy to achieve desired performance, which necessitates a precise and efficient mechanism. Furthermore, a positioning assembly that provides movement about one or more axes may experience gravitational load, wind load, or occasional seismic load, which may produce back-driving of the positioning assembly. If back-driving occurs over a relatively large angular range, such back-driving can be not only an operational hazard, it can also be a safety concern if a failure of a component of the positioning assembly occurs. In addition, resistance to back-driving might dictate that an antenna positioning system has relatively high friction, which may produce challenges in providing precise movement for achieving the desired accuracy.